“…We propose that 'reinsertion of the NG tube' should be adopted as the standardized definition in the future to allow meaningful prospective studies that evaluate the risk factors for PPOI and strategies for prevention. [65] Abdominal distension or vomiting, based on clinical judgement Kahokehr, 2010 [42] NR Singh, 2011 [69] Abdominal distension or vomiting, based on clinical judgement Abodeely, 2011 [38] NR Raue, 2011 [43] NR Pelloni, 2012 [59] NR Kim, 2013 [34] NR Kolozsvari, 2013 [52] NR Manceau, 2013 [56] NR RCTs Ortiz, 1996 [22] Two episodes of vomiting Ortiz, 1996 [31] Two episodes of vomiting Schwenk, 1998 [23] NR Stewart, 1998 [25] Vomiting of > 100 ml on two occasions within 24 h Smith, 2000 [24] Clinical judgement Targarona, 2002 [32] NR Taqi, 2007 [26] NR Hewett, 2008 [30] NR El Nakeeb, 2009 [19] Two episodes of vomiting without bowel movement Kang, 2010 [29] NR Ng, 2010 [21] NR Deng, 2013 [18] NR Zaghiyan, 2013 [28] NR NG, nasogastric; NR, not reported.…”